1. Technical Field
The following description relates to a printing device having a time-designating function to execute a printing operation at a designated (programmed) time, and a printing system employing such a printing device.
2. Related Art
Conventionally, a printing device having a time-designating function has been known. An example of such a printing device is disclosed in Japanese Patent Provisional Publication No. 2003-220742 (hereinafter, referred to as '742 publication). The printing device disclosed in '742 publication is also provided with a power saving function (e.g., a so-called sleeping function). That is, if a print request has not been received for a predetermined period of time, an operation mode of the printing device is switched from a normal mode, in which the printing can be executed immediately upon receipt of the print request), to the power saving mode. When the operation mode is switched between the power saving mode and the normal mode, an ON/OFF state of some components of the printing device (e.g., a fixing unit of a laser beam printer) is changed. In particular, when the operation state is changed from the power saving mode to the normal mode, a power consumption of some components may be temporarily larger than the power consumption in the normal mode since, for example, the operating status of the fixing unit should be changed to the normal mode within a relatively short period of time. Therefore, it is not preferable that the switching between the normal mode and the power saving mode occurs frequently in view of the power consumption.
According to the '742 publication, when a print job corresponding to a certain printing request is to be executed, it is checked whether a time-designated print job is in a printing queue. If the time-designated print job to be executed at a designated time is in the print queue, and the designated time is relatively close to the current time, at which the current print job is to be executed, the designated time of the time-designated print job is changed so that the time-designated print job is executed immediately after the current print job. With such a conventional configuration, the frequency of the mode change can be reduced, thereby the power consumption being reduced.